<template>
<div class="category">
  <!--显示所有上架的父分类-->
  <ul>
    <li @click="selectFirstCategory({})" :class="{active:!firstCategorySelected.id}">全部</li>
    <li v-for="(category,index) in firstCategoryList"
        :key="index"
        :class="{active:category.id == firstCategorySelected.id}"
        @click="selectFirstCategory(category)"
    >{{ category.name }}</li>
  </ul>
<!-- 显示父分类下的子分类 -->
  <ul v-if="firstCategorySelected.id">
    <li @click="selectSecondCategory({})" :class="{active:!secondCategorySelected.id}">全部</li>
    <li v-for="(category,index) in secondCategoryList"
        :key="index"
        @click="selectSecondCategory(category)"
        :class="{active:category.id == secondCategorySelected.id}"
    >{{ category.name }}</li>
  </ul>

</div>
  <!-- 显示搜索到的商品 -->
  <div class="goodsList">
    <ul>
      <li v-for="(goods,index) in pageInfo.list" :key="index" @click="toGoodsView(goods.id)">
        <div class="pic"><el-image :src="`${SERVER_ADDR}/goods/pic/${goods.picList[0].url}`" /></div>
        <div class="name">{{ goods.name }}</div>
        <div class="dscp">{{ goods.dscp }}</div>
        <div class="price">$ {{ goods.price }}</div>
      </li>
    </ul>
    <el-row class="row-bg" justify="center" style="margin-top: 20px;">
      <el-pagination layout="prev, pager, next" :total="pageInfo.total" :page-size="pageInfo.pageSize"
                     @change="search"/>
    </el-row>
  </div>
</template>

<script setup>
//获取通过路径传递的参数
import {ref, watch} from "vue";
import categoryApi from "@/api/categoryApi.js";
import goodsApi from "@/api/goodsApi.js";
import {useRouter} from "vue-router";

const router = useRouter();

const props = defineProps({
  categoryId:String
});
//服务器地址
const SERVER_ADDR = ref(import.meta.env.VITE_SERVER_ADDR)
//所有需要显示的父分类
const firstCategoryList = ref([])
//所有需要显示的子分类
const secondCategoryList = ref([])
//被选中的父分类
const firstCategorySelected = ref({})
//被选中的子分类
const secondCategorySelected = ref({})
//被选中的分类id - 可能是父分类id也可能是子分类id
const categoryId = ref(null);
//分页信息
const pageInfo = ref({
  pages: 0,
  pageSize: 0,
  pageNum: 0
});

//点击父分类调用函数
function selectFirstCategory(category){
  //给选中的父分类赋值
  firstCategorySelected.value = category;
  //只要选择某个父分类，就要清空所有要显示的子分类
  secondCategoryList.value=[];
  //给被选中的分类id赋值
  if(firstCategorySelected.value.id){
    categoryId.vaule = firstCategorySelected.value.id;
  }else {
    categoryId.vaule = null;
  }
  //给被选中的父分类下的子分类赋值
  if(category.childList){
    category.childList
        .filter(c => c.status == 1)
        .forEach(c => secondCategoryList.value.push(c))
  }
  //查询商品
  search(1);
}


//点击子分类调用函数
function selectSecondCategory(category){
  //给选中的子分类赋值
  secondCategorySelected.value = category;
  //给被选中的分类id赋值
  if(secondCategorySelected.value.id){
    categoryId.vaule = secondCategorySelected.value.id;
  }else {
    categoryId.vaule = firstCategorySelected.value.id;
  }
  //查询商品
  search(1);
}

//1.获取父分类 2.上架 3.推荐
function getParent(){
  const condition = {
    parentId:0,
    recom:1,
    status:1
  };
  categoryApi.selectByPage(condition)
      .then(resp => {
        firstCategoryList.value = resp.data;
        //假设没有通过路径传递参数或者传递的id在父分类中不存在
        let flag = true;
        firstCategoryList.value.forEach(c => {
          if(props.categoryId == c.id){
            flag = false;
            selectFirstCategory(c);
          }
        })
        //假设成立
        if(flag == true){
          //父分类设置选择全部
          selectFirstCategory({});
        }
      });
}
//搜索
function search(pageNum){
  const condition = {
    status: 1,
    categoryId:categoryId.vaule
  };
  goodsApi.selectByPage1(condition,pageNum,20)
      .then(resp => {
        pageInfo.value = resp.data;
      })
}

//跳转到商品详情页面
function toGoodsView(id){
  router.push({
    path:'/user/goods', //跳转到的位置，值和页面路由种的配置的路径相同
    query:{
      id
    }
  });
}

//通过路径传递参数发生变化的处理
watch(props,() => {
  getParent()
})

getParent();
</script>

<style scoped>
.category ul li {
  float: left;
  margin: 10px 20px;
  font-size: 14px;
  cursor: pointer;
}
.active{
  color: var(--theme-color);
  font-weight: bold;
}
.goodsList ul li{
  width: 224px;
  float: left;
  margin-right: 20px;
  text-align: center;
  background-color: #EEE;
  margin-bottom: 20px;
  cursor: pointer;
}
.goodsList ul li:hover{
  box-shadow: 0px 0px 20px #000;

}
.goodsList ul li:nth-child(5n){
  margin-right: 0px;
}
.name,.dscp,.price{
  line-height: 25px;
}
.name{
  font-size: 16px;
  font-weight: bold;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}
</style>